Free health calculator

Daily Calorie Needs Calculator

Q: What is the difference between BMR, RMR and TDEE?

BMR refers to basal metabolic rate under tightly controlled resting conditions. RMR refers to resting metabolic rate and is generally measured under less restrictive conditions. The terms are often used loosely in online calculators. TDEE means total daily energy expenditure. It includes resting energy plus estimated energy used through digestion, everyday movement and exercise. This calculator’s maintenance result is an estimated TDEE.

Estimate how many calories your body may need each day based on your age, sex, height, weight and usual activity level.

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Enter your details

This calculator is designed for adults aged 18 years and older.

Age Adults aged 18–100

Sex used by the equation

Male

Female

Height in centimetres

Height

Weight in kilograms

Weight in pounds

Usual activity level Include both structured exercise and your normal daily movement.

Your estimate will appear here

Enter your details and select your usual activity level to calculate your estimated daily calorie needs.

Estimated maintenance calories

0 calories per day

Estimated resting needs 0 calories per day

Estimated weekly needs 0 calories per week

Activity level used —

Illustrative planning ranges

These are simple examples based on 10% below or above the maintenance estimate. They are not personalised targets.

Approximately 10% below maintenance 0 calories

Estimated maintenance 0 calories

Approximately 10% above maintenance 0 calories

This estimate uses the Mifflin–St Jeor resting-energy equation and the activity level you selected. Actual calorie needs can differ.

Resting Energy Estimate

This estimates the energy your body uses while at rest to support essential functions such as breathing, circulation, temperature regulation and normal organ function.

It does not represent your full daily calorie requirement because it does not yet account for normal movement, work or exercise.

Sometimes described as BMR or RMR

Maintenance Calories

Your maintenance result estimates the calories you may need each day to keep your current body weight relatively stable at the activity level you selected.

This is often called total daily energy expenditure, or TDEE. It includes your resting needs plus estimated daily activity.

Resting estimate × activity factor

Goal Estimates

The weight-loss and weight-gain figures use a modest 10% adjustment below or above your estimated maintenance calories.

They are general starting points—not promises of a particular weekly weight change. Individual responses can vary considerably.

Approximately 10% below or above maintenance

How to Use Your Result

Treat the number as an informed starting estimate and refine it using your real-world results.

Start near the appropriate estimate Choose maintenance, gradual loss or gradual gain based on your goal and personal circumstances.
Follow it consistently for several weeks Daily body weight can fluctuate, so look for a general trend rather than reacting to a single measurement.
Review and adjust gradually If your longer-term trend does not match your goal, reassess your activity choice and make a modest adjustment if suitable.

Estimate Resting Needs

Age, sex, height and weight are entered into the Mifflin–St Jeor equation.

Apply Activity Level

The resting estimate is multiplied by the activity factor you selected.

Show Planning Estimates

The calculator displays maintenance and modest goal-based calorie estimates.

The Mifflin–St Jeor Equation

This published predictive equation estimates resting energy expenditure using body weight, height, age and a sex-specific constant.

Equation for males (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5

Equation for females (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

Measurement note: Imperial measurements are converted to kilograms and centimetres before the equation is applied.

How Activity Changes the Estimate

Your resting estimate is multiplied by the factor associated with your selected activity level. Because activity can be difficult to judge precisely, this selection can significantly affect the result.

Activity level	General description	Multiplier
Sedentary	Mostly sitting with little planned exercise	1.20
Lightly active	Light exercise or sport approximately 1–3 days a week	1.375
Moderately active	Moderate exercise or sport approximately 3–5 days a week	1.55
Very active	Hard exercise or sport approximately 6–7 days a week	1.725
Extremely active	Intensive training, very demanding exercise or a highly physical occupation	1.90

Body Size

Larger bodies generally require more energy to maintain basic functions and move through daily life. This is why both height and weight are included in the calculation.

Included directly in the calculator

Body Composition

Muscle and other lean tissues generally use more energy than fat tissue. Two people with the same body weight may therefore have different resting energy expenditure.

Not measured by this calculator

Age

Estimated resting energy needs commonly change with age. Changes in muscle mass, body composition, hormones and activity can also contribute over time.

Included directly in the calculator

Daily Movement

Walking, standing, household tasks, physical work and spontaneous movement can add substantially to daily energy expenditure—even when they are not considered formal exercise.

Estimated through your activity selection

Exercise and Training

Exercise frequency, intensity, duration and type all matter. Training volume can also vary significantly from one week or season to another.

Choose the activity level that reflects a typical week

Health and Life Stage

Pregnancy, breastfeeding, growth, illness, recovery, some health conditions and certain medicines may change nutritional or energy requirements.

Requires individual assessment

Your Activity Level Is More Than Exercise

A one-hour workout is only one part of your day. The amount of time you spend walking, standing, driving, sitting, doing housework or working physically can also affect your total daily energy expenditure.

When choosing an activity level, think about an ordinary week—not your most active day. If you are uncertain between two options, the lower level is often a more conservative starting estimate.

Planned workouts and sport
Walking and daily errands
Standing versus sitting time
Household and gardening tasks
Physical demands of your work

About 10% below maintenance

Gradual Weight Loss

Choose this estimate if gradual weight loss is appropriate for you and you want a conservative starting point below your predicted maintenance needs.

The calculator uses a modest 10% reduction rather than an aggressive fixed deficit. This does not guarantee a particular rate of weight loss.

Remember Sustainable habits and overall diet quality matter more than reaching an exact calorie number every day.

Estimated energy balance

Weight Maintenance

Choose the maintenance estimate if you want to keep your current weight relatively stable or first learn how closely the calculator matches your real energy needs.

Maintenance can also provide a useful baseline before deciding whether a calorie adjustment is necessary.

Remember A stable trend over several weeks is more informative than normal day-to-day weight fluctuations.

About 10% above maintenance

Gradual Weight Gain

Choose this estimate if gradual weight gain is suitable for you, such as when supporting a planned muscle-building goal alongside appropriate resistance training.

The calculator uses a modest 10% increase. Food quality and adequate protein remain important; additional calories alone do not ensure that weight gained will be muscle.

Remember Unintentional weight loss or difficulty gaining weight should be discussed with a health professional.

Before Choosing a Target

Consider your wider health and circumstances—not only the number produced by the calculator.

Has your weight been broadly stable, increasing or decreasing without you intending it to?
Does the activity level you selected reflect an ordinary week rather than an unusually active or inactive one?
Can your chosen target still support balanced meals and adequate nutrition?
Do you have a medical condition, take medicines or have a life stage that may change your nutritional needs?

Use Trends to Refine the Estimate

Calorie calculations are starting points. Follow the same general approach consistently and assess the overall pattern rather than changing your target in response to a single day.

Weight trend Compare measurements taken under reasonably similar conditions and focus on the longer-term direction.

Energy and wellbeing Notice persistent fatigue, dizziness, weakness, poor concentration or difficulty completing normal activities.

Activity changes Recalculate when your work, exercise routine or everyday movement changes meaningfully.

Vegetables and Legumes

Include different types and colours across the week.

Fruit

Choose a variety of whole fruits where practical.

Grain Foods

Emphasise wholegrain and higher-fibre choices.

Protein-Rich Foods

Include lean meats, fish, eggs, tofu, legumes, nuts or seeds.

Dairy or Alternatives

Include milk, yoghurt, cheese or suitable alternatives.

You do not need to include every food group at every meal. Aim for appropriate variety across the day and week.

A Flexible Meal-Building Check

Instead of trying to make every meal perfect, use these prompts to help build meals that contribute useful energy and nutrients.

Is there a suitable source of protein?
Can you include vegetables, legumes or fruit?
Is there a wholegrain or other suitable carbohydrate source?
Does the meal include appropriate healthy fats where needed?
Is the portion suitable for your hunger, needs and goal?
Are water and regular hydration available throughout the day?

Emphasise More Often

Vegetables, legumes and whole fruit
Wholegrain and higher-fibre foods
Varied protein-rich foods
Unsaturated fats in suitable portions
Water as the main drink

Keep in Perspective

Foods high in added sugars
Foods high in saturated fat
High-salt foods and frequent processed snacks
Sugar-sweetened drinks
Alcohol, where consumed

Calories and kilojoules are different units of food energy Australian food labels usually display energy in kilojoules.

1 dietary Calorie (1 kcal) = 4.184 kJ

Overestimating Your Activity Level

It is easy to focus on planned workouts while overlooking the many hours spent sitting. Selecting an activity category that is too high can noticeably increase the maintenance estimate.

Better approach: Consider your full week—including your occupation, commuting, sitting time, daily steps and exercise. When genuinely unsure between two levels, begin with the lower estimate and review the trend.

Treating the Result as an Exact Prescription

Predictive equations estimate average energy needs. They cannot directly measure your metabolism, body composition or every movement you make throughout the day.

Better approach: Use the result as a starting range and refine it gradually using your longer-term response.

Reacting to One Day of Scale Change

Body weight can move from day to day because of fluid balance, food still being digested, carbohydrate storage, sodium intake and normal measurement variation.

Better approach: Look at the general pattern over several weeks rather than changing your calorie target after one measurement.

Counting Some Foods but Forgetting Others

Cooking oils, sauces, dressings, drinks, small snacks and larger portions can contribute energy even when they do not feel like part of a main meal.

Better approach: If you choose to track, be consistent enough to identify your usual pattern without expecting perfect precision.

Reducing Calories Too Aggressively

A larger deficit is not automatically better. Excessive restriction can make an eating plan difficult to sustain and may make it harder to obtain adequate energy and nutrients.

Better approach: Begin with a modest, sustainable change. Do not repeatedly cut intake because progress is slower than expected.

Ignoring Health, Hunger and Wellbeing

A number may appear reasonable while the eating pattern used to reach it leaves you persistently hungry, weak, dizzy, fatigued or preoccupied with food and weight.

Better approach: Consider energy, mood, training, concentration, hunger and overall wellbeing—not only the calorie total or scale.

Real-World Results Help Refine the Calculation

If your average body weight remains broadly stable over time, your average energy intake is probably relatively close to your actual expenditure—even if it differs from the calculator’s prediction.

Before changing the target, check whether your activity level, measurement units and usual intake have been represented accurately. Then make only a modest adjustment where appropriate.

Most useful evidence Your longer-term trend Not one meal, one workout, one day or one scale reading

How accurate is the Daily Calorie Needs Calculator?

The calculator provides an informed estimate, not an exact measurement. It uses the Mifflin–St Jeor equation to estimate resting energy needs and then applies an activity multiplier. Actual requirements can differ because of body composition, genetics, health, medicines and variations in daily movement. Your longer-term weight trend can help you assess how closely the estimate matches your real needs.

How many calories do I need to maintain my weight?

The maintenance result estimates the number of calories you may need each day to keep your current weight relatively stable at the activity level selected. Because energy expenditure changes from day to day, it is better treated as a starting range than as one exact number that must be reached every day.

How many calories should I eat to lose weight?

There is no universal weight-loss calorie target. This calculator displays a gradual-loss estimate approximately 10% below predicted maintenance as a conservative starting point. It does not guarantee a particular rate of weight loss. Changes should be gradual, nutritionally adequate and sustainable. Seek personalised advice if you have a medical condition, use relevant medicines or have a history of disordered eating.

How many calories should I eat to gain weight?

The calculator displays a gradual-gain estimate approximately 10% above predicted maintenance. This is only a general starting point. Weight gain should still be supported by a varied, balanced eating pattern. Speak with a doctor if you have lost weight unexpectedly, have difficulty gaining weight or have symptoms that may affect eating or digestion.

What is the difference between BMR, RMR and TDEE?

BMR refers to basal metabolic rate under tightly controlled resting conditions. RMR refers to resting metabolic rate and is generally measured under less restrictive conditions. The terms are often used loosely in online calculators.

TDEE means total daily energy expenditure. It includes resting energy plus estimated energy used through digestion, everyday movement and exercise. This calculator’s maintenance result is an estimated TDEE.

Which activity level should I choose?

Choose the level that best reflects an ordinary week, including planned exercise, walking, standing, sitting and the physical demands of your work. Do not base the selection only on your most active day. If you are genuinely unsure between two categories, beginning with the lower level provides a more conservative estimate that can later be reviewed.

Should I eat fewer calories than my resting energy estimate?

A resting energy estimate is not automatically a safe minimum intake or a personal calorie prescription. Your body also needs energy for digestion, daily movement and exercise. Regularly eating below the displayed resting estimate without appropriate supervision may make nutritional adequacy harder to achieve. Seek guidance from a doctor or accredited practising dietitian before using a highly restrictive target.

How often should I recalculate my calorie needs?

Recalculate after a meaningful change in body weight, activity level, occupation, training schedule or normal daily routine. There is usually no benefit in recalculating after every small weight fluctuation. Use a longer-term pattern and make gradual adjustments when appropriate.

Can children and teenagers use this calculator?

No. This calculator is designed for adults aged 18 years and older. Children and teenagers have energy needs related to growth and development, so adult predictive equations and weight-loss targets may be inappropriate. A parent or guardian should discuss concerns about a young person’s growth, eating or weight with a doctor or paediatric dietitian.

Can I use this calculator during pregnancy or breastfeeding?

This calculator is not designed to estimate the additional energy and nutritional requirements associated with pregnancy or breastfeeding. Needs also vary according to pregnancy stage, health and individual circumstances. Ask your doctor, midwife or accredited practising dietitian for personalised guidance.

Why does the calculator ask for male or female?

The published Mifflin–St Jeor equation uses different sex-specific constants for males and females. This binary input is a limitation of the equation and may not accurately reflect every person’s physiology, including some people receiving gender-affirming hormone therapy. A qualified health professional can provide a more individualised assessment.

What is the difference between calories and kilojoules?

Calories and kilojoules are two units used to measure energy. Australian food labels usually display kilojoules. One kilocalorie—commonly called one food calorie—is approximately 4.184 kilojoules. To convert this calculator’s result to kilojoules, multiply the calorie figure by approximately 4.184.

Does the calculator save or send my personal information?

No. The details entered into this calculator are processed within your browser to display your result. The calculator does not store your entries in an account or send them to Everything Calculated.

Final takeaway

Use Your Result as a Starting Point

Your estimated calorie needs can help with planning, but the most useful target is one that reflects your real activity, supports adequate nutrition and can be adjusted gradually using your longer-term results.

Begin With the Estimate Select the result that matches your current goal and treat it as an initial planning figure.

Follow the Longer-Term Pattern Avoid reacting to one day of eating, exercise or body-weight fluctuation.

Adjust Carefully Reassess your inputs and make gradual changes when your real-world trend differs from the estimate.

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No account required Information stays on your device Evidence-informed calculation

Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA and Koh YO. A New Predictive Equation for Resting Energy Expenditure in Healthy Individuals. The original 1990 research paper describing the Mifflin–St Jeor resting-energy equation used by this calculator. View the PubMed record
National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Energy. Comprehensive 2023 review of estimated energy requirements, energy expenditure and the limitations of predictive equations. Read the National Academies report
Australian Government — Eat for Health: Dietary Energy Information about basal metabolism, physical activity levels and estimated energy requirements for adults. Read the dietary-energy guidance
Australian Government — Eat for Health: The Five Food Groups Guidance on obtaining a variety of nutrients through the five core food groups. Explore the five food groups
Healthdirect Australia: Kilojoules Consumer health information about energy balance, calories, kilojoules and factors influencing energy needs. Read about calories and kilojoules
Healthdirect Australia: Weight Loss and Dieting Australian guidance emphasising balanced nutrition and small, gradual and sustainable dietary changes. Read the weight-management guidance
Healthdirect Australia: A Balanced Diet Practical information about balanced eating, food variety and the five food groups. Read the balanced-diet guidance

Calculation transparency: The calculator uses the simplified Mifflin–St Jeor equations: weight in kilograms × 10, plus height in centimetres × 6.25, minus age × 5, then plus 5 for males or minus 161 for females. The result is multiplied by the activity factor selected by the user.